Scheduler.js

Scheduler.js is a simple client side scheduler based on the requestAnimationFrame loop. Typically you may use something like window.setInterval() or window.setTimeout() to achieve this.

However, requestAnimationFrame allows us to utilize the GPU, avoiding the performance bottlenecks of those other methods. requestAnimationFrame is intended to allow Javascript animations to utilize the computer's GPU so it can be handled at ~60fps (performance depends on the machine). Scheduler just makes it easy to control multiple tasks running on the requestAnimationFrame loop.

NOTE: This plugin will make it really, really, really easy to bog down your app. Schedule with caution.

Usage

Create a new instance of Scheduler:

var scheduler = new Scheduler;

Now let's schedule something:

var foo = function () {
  console.log('Do a thing.');
};
 
scheduler.schedule('foo', foo);

Then let's stop it:

scheduler.unschedule('foo');

Boom. Now let's get crazy:

var fooCounter = 0;
var barCounter = 0;
 
var foo = function () {
  console.log('foo has run ' + fooCounter + ' times.');
  fooCounter++;
};
 
var bar = function () {
  console.log('bar has run ' + barCounter + ' times.');
  barCounter++;
};
 
scheduler.schedule('foo', foo);
scheduler.schedule('bar', bar);
 
setTimeout(function () {
  scheduler.unschedule('foo');
}, 1000)

Scheduler will be happy to run as many tasks as you want to give it.

API

new Scheduler

Creates and returns a new instance of Scheduler.

Scheduler.schedule(taskId, task[, context])

The schedule() method adds a task to the schedule, causing it to run on every iteration of the schedule loop. Returns the task's ID.

Parameter	Required/Optional	Description
taskId	optional	A string used to manipulate the task within the context of the Scheduler. If an ID is not passed then the task's ID will be it's index in Scheduler.tasks.
task	required	The function to be run.
context	optional	A value to be used for this inside the task.

Scheduler.unschedule(taskId)

The unschedule() method removes a task from the schedule and stops it from running. Returns a success boolean.

Parameter	Required/Optional	Description
taskId	required	The task to be removed from the schedule. This will completely remove the task from the Scheduler so it cannot be restarted.

Scheduler.pause([taskId])

The pause() method pauses a task without removing it from the schedule. The task can later be restarted with start().

Parameter	Required/Optional	Description
taskId	optional	The task to be paused. If no taskId is passed, the entire scheduler will be paused.

Scheduler.start([taskId])

The start() method restarts a paused task.

Parameter	Required/Optional	Description
taskId	optional	The task to be started. If no taskId is passed, the entire scheduler will be started.

Scheduler.clear()

Removes all tasks from the scheduler.